This drilled and tapped M & M replacement wheel fits APQS machines with electronic channel locks. These smooth-running wheels designed by APQS engineer Mike Moore glide across the aluminum rails for effortless quilting. The special hard polymer resists dirt accumulation and oxidation, and the sealed wheel bearings extend wheel wear. NOTE: If you are looking for replacement wheels for older style "brown" or "black" Ralmark wheels, they are no longer available. You must replace your current wheels in "sets" and purchase a complete M & M carriage wheel kit and/or M & M sewing head kit. M & M wheels work on all APQS machines using a horizontal wheel position, and are part of the APQS Bliss Drive Quilting System. Complete M & M Wheel Kits including installation hardware are available.